Continuous Casting Installation with at Least One Robot and Method for Operating a Continuous Casting Installation Including at Least One Robot

ABSTRACT

A continuous casting installation is equipped with at least one robot for carrying out process-controlled or automated interventions on the continuous casting installation and accessing the assigned auxiliary devices. To ensure optimum use of the robot(s), the continuous casting installation is assigned a runway, the robot is assigned a travelling mechanism and the travelling mechanism is displaceably guided on the runway, at least one parking position and at least two operating positions are defined for the robot on the runway and each operating position is assigned working areas on the continuous casting installation that can only be reached from this operating position, the distance between each operating position of the robot and the assigned operating area or supply area is fixed within the minimum and maximum range of the robot arm and the robot is equipped with a data transmitting and receiving device and the latter is connected by signalling technology to a central control device or a process computer of the continuous casting installation. Furthermore, the invention comprises a method for operating a continuous casting installation including at least one robot which can be displaced on a runway between a parking position and at least two operating positions.

The invention relates to a continuous casting installation with at leastone robot for carrying out process-controlled or automated interventionson the continuous casting installation and accessing assigned auxiliarydevices. Furthermore, the invention relates to a method for operating acontinuous casting installation including a robot.

The present invention extends to all types of continuous castinginstallations in which molten metal from a molten metal container, suchas for example a casting ladle, is directed via a tundish into a chilledmould, shaped there under intensive cooling to form an at least partlysolidified strand of any desired cross section and continuously conveyedout of the continuous casting installation. According to thecharacteristics of the moulds that are used, the casting installationsmay be equipped with oscillating tubular and plate moulds, track moulds,rotating casting rolls with side plates (two-roll casting installations)or moulds with circulating belts. The strands may have cross sections ofslabs, thin slabs, strips, blooms or billets and any other desiredpreliminary shaping cross sections of any desired dimensions.

Robots are used on a continuous casting installation for carrying outrecurrent work and to eliminate operating problems in hazardous areas inwhich the operating personnel are subjected to great heat exposure,emanating from the liquid metal and the cast metal strand, or spatteredslag and metal. Robots are already used at the open continuous castingmould to observe the surface of the molten bath, to eliminate depositsbaked on the inner sides of the mould walls, to feed in casting powder,to measure temperatures and take samples and the like. Furthermore,robots are used for changing the shroud, changing the casting tube andfor changing closure plates of the side gate nozzle and for blowing openthe outflow opening at tundishes and casting ladles. Furthermore, it isknown to use robots for inspecting the cast strands or the cut-offslabs, blooms and billets and for the elimination of defects, forexample by flaming, in the outlet region of a continuous castinginstallation.

For example, the use of a multifunctional robot on a continuous castingmould is already known from EP-B 371 482, the robot on the one handreceiving data relating to the casting process from measuring devices onthe mould and on the other hand acquiring measuring data itself on themould by a detection system, for example an optical detection system,and using this information to prepare and implement a plan of actionwith priority assignment. A stationary robot is concerned here, thelocation of which is chosen specifically for use on the mould and isaccordingly not suitable for performing activities likewise occurring inareas of the continuous casting installation neighbouring the continuouscasting mould.

Robots which are likewise assigned to a single working area at acontinuous casting installation are known from U.S. Pat. No. 5,067,553,JP-A 5-169206, JP-A 9-109100, JP-A 7-60434 and JP-A-293615.

More extensive use of robot technology on the casting platform of acontinuous casting installation previously led to a massing of suchrobots and to confused operations proceeding in confined spaces. JP-A3-71959 discloses the use of two robots on a casting platform of amultistrand continuous casting installation, each robot being assigned arunway and the robot being able to assume an operating position on thisrunway to exchange casting tubes on a large tundish and carry outcleaning work at the outlet openings of the tundish and the castingtubes. Each robot is assigned a demarcated working area, it not beingpossible for one robot to work in the working area of another robot, sothat if one robot fails the other robot cannot take over this work andinterventions on the continuous casting installation by the operatingpersonnel are necessary. Altogether, the proliferation of robotsincreases the investment costs and operating costs, without at the sametime achieving improved availability of the individual robot.

The object of the present invention is therefore to avoid thesedisadvantages and difficulties of the known prior art and to propose acontinuous casting installation with at least one robot of the typedescribed at the beginning and a method for operating a continuouscasting installation including a robot, with which differentinterventions on a continuous casting installation can be carried out atvarious working positions which lie outside the range of a singleoperating position of a robot.

A further aim of the invention is to increase the degree of utilizationand the availability of the robot or robots used.

This object is achieved according to the invention by the continuouscasting installation being assigned a runway, by the robot beingassigned a travelling mechanism and the travelling mechanism beingdisplaceably guided on the runway, by at least one parking position andat least two operating positions being defined for the robot on therunway and each operating position being assigned working areas on thecontinuous casting installation that can only be reached from thisoperating position, by the distance between each operating position ofthe robot and the assigned operating area or supply area being fixedwithin the minimum and maximum range of the robot arm and by the robotbeing equipped with a data transmitting and receiving device and thelatter being connected by signalling technology to a central controldevice or a process computer of the continuous casting installation.

The fixing of a runway on the continuous casting installation, or inzones of a continuous casting installation, which is taken past a numberof potential working areas in such a way that these working areas liewithin the range of predetermined operating positions of a robot whichcan be made to move on the runway has the effect of overcoming therestricted, only single operating capability of the robot and creating amuch more efficient operating capability. Depending on demand, the robotcan be guided by a central control device or the process computer of thecontinuous casting installation to each desired operating position andcarry out the interventions necessary there.

Operating positions for the robot define locations of the robot alongthe runway from which one or more working areas on the continuouscasting installation lie within the range of the robot gripper. Inembodiments of the robot in which the robot stand is secured on thetravelling mechanism fixedly or rotatably about a vertical axis, theoperating positions of the robot on the runway are defined by theposition of the travelling mechanism alone. In the case of embodimentsof the robot in which a swiveling mechanism with a jib is arranged onthe travelling mechanism, and the actual robot is only fastened on theprojecting end of the jib, the swiveling angle of the jib of theswiveling mechanism is also decisive in addition to the position of thetravelling mechanism for defining the operating position of the robot.

Working areas of the robot are special areas or individual locations onthe continuous casting installation where interventions are performed bythe robot, starting from a predetermined operating position.

Supply areas comprise, in spatial terms, storage places with auxiliarydevices, such as tool stores, utility stores and similar devices, whichhave fixed positions for tools, spare parts and utilities to be receivedand deposited by the robot. Stored in the auxiliary devices are firstlytools for the robot that are required for carrying out theinterventions, such as for example tongs, measuring probes, grindingheads, secondly spare parts for the continuous casting installation,such as casting tubes or slide valve plates, and thirdly utilities forthe continuous operation of the continuous casting installation, such asfor example casting powder. The tool stores and utility stores providedin the respective supply areas may be formed by stationary or mobileauxiliary devices, the mobile auxiliary devices, for example a utilitiescarriage, possibly only being brought into the supply area of a specificoperating position when required, and stocked up away from its supplyingposition.

The parking position is defined as the position of the robot on therunway at which it stops when it is carrying out interventions and waitsfor a new operating signal from the central control device or theprocess computer. When a number of robots are assigned to one runway, anumber of parking positions are accordingly defined. In the case of tworobots, the two parking positions are preferably arranged at oppositeends of the runway.

The carrying out of process-controlled or automated interventions by therobot also comprises the alternative possibility of an intervention thatis manually remote-controlled by the operating personnel. These manuallyremote-controlled interventions can take place from the control room orby means of other portable control units.

The runway for the robot is preferably formed by a track system or by atleast one running rail in the manner of an overhead monorail conveyor orcraneway. Moving to predetermined operating positions is achieved bycorresponding control devices (position transmitters, displacementmonitoring systems).

To be able to serve a multiplicity of working areas on the continuouscasting installation, it is expedient if the runway has branches withthe inclusion of customary points. This allows operating positions awayfrom a main runway to be defined and assumed and a number of robots canbe used without them hindering one another.

Alternatively, individual sections of the runway are formed in such away that they can be adjusted in height by means of lifting mechanismsor can be swiveled by swiveling mechanisms, in order to change theoperating position of the robot on the runway in such a way thatbest-possible access to the assigned operating area is achieved.

Each robot is assigned a travelling mechanism, on which it is supportedor suspended, depending on the design of the runway. To increase thesize of its operating area, the travelling mechanism may be assigned arobot swiveling mechanism, whereby at least two operating positions aredefined for the robot with the swiveling position of the robot swivelingmechanism. The swiveling mechanism preferably comprises an extendingjib, on the extending end of which the robot is arranged. The jib may beadapted to requirements of the operating environment, possibly forexample also made adjustable in height.

The robot is preferably fixed in its respective operating position by anarresting device, to avoid positional changes caused by reaction forcesfrom the interventions.

To be able to carry out interventions on the continuous castinginstallation as quickly and efficiently as possible, it is expedient ifeach operating position of the robot on the runway is assigned at leastone operating area at the continuous casting installation and a supplyarea at an auxiliary device, such as for example a tool store or autilities store.

Consequently, all the utilities necessary for carrying out anintervention are available for the robot within the range of its robotarm, without it having to perform additional manipulating movements tochange the tool or transport the spare part.

The runway may extend along the entire continuous casting installationand at different heights and may also comprise upward and downwardslopes, preferably when the runway is formed as a running rail of anoverhead conveyor. The runway is preferably restricted to the castingplatform and/or to the delivery area of the continuous castinginstallation. Here, the runways are preferably arranged in a horizontalplane.

According to a preferred refinement, two robots are arranged on onerunway, one robot preferably performing the interventions on thecontinuous casting installation as the primary robot and the secondrobot being used as an auxiliary robot when there are conflicts ofpriority for the work to be carried out and when there are problems withthe primary robot. A different distribution between the robots of thework to be carried out, for example by priority assignment of individualrobots to specific operating positions or assignment by manual remotecontrol is quite possible, and is within the scope of the invention.

The invention also comprises a method for operating a continuous castinginstallation including at least one robot which can be displaced on arunway between a parking position and at least two operating positionsand is characterized in that control signals are issued from a processcomputer or a central control device to the robot and, on the basis ofthese control signals, a selected operating position is moved to andautomated interventions on the continuous casting installation areperformed by the robot, the control signals for the interventions to becarried out on the continuous casting installation being issued by theprocess computer or a central control device to the robot in thesequence of the priority of the interventions to be carried out.

The operation of the robot is defined and controlled by the processcomputer of the continuous casting installation or a central controldevice, the activities to be carried out being determined with regard tothe quality of the products to be produced. The basis for the priorityassignment is formed by a continuous diagnosis of the casting process,consequently the continuously gathered measurement data and modelcalculations in comparison with default data.

The robot itself also carries out on the continues casting installationobservations of the state of the casting process as it proceeds andgathers measurement data. These measurement data are transmitted to theprocess computer or a central control device, are processed by theprocess computer or the control device and results of this dataevaluation are converted into control signals for the robot or thecontinuous casting installation.

When at least two robots which can be made to move on a runway are used,a first robot which can be made to move on the runway, as the primaryrobot (master robot), receives all the control signals and carries outinterventions on the continuous casting installation and a further robotwhich can be made to move on the runway, as the auxiliary robot (slaverobot), is preferably assigned to a parking position.

If there is a conflict of priorities of control signals, the primaryrobot and the auxiliary robot are activated and both robots are directedto the respective operating positions while excluding the possibility ofthem hindering one another.

Further advantages and features of the present invention emerge from thefollowing description of non-restrictive exemplary embodiments,reference being made to the accompanying figures, in which:

FIG. 1 shows a schematic representation of the operating capabilities ofone or two robots on the casting platform of a continuous castinginstallation,

FIG. 2 shows a robot swiveling mechanism with two operating positions ofthe robot in an elevation,

FIG. 3 shows the robot swiveling mechanism according to FIG. 2 with twooperating positions on the casting platform in a plan view,

FIG. 4 shows a robot runway with a runway section which can bevertically raised and lowered,

FIG. 5 shows a robot runway with a runway section which can be swiveledin a horizontal plane.

On the casting platform 1 of a continuous casting installation, thelayout of which is in no way restricted, the outlines are shown of acasting ladle 2 with a ladle nozzle 3 (shroud) and a tundish 4positioned under it, with a submerged casting tube 5, which protrudesinto a continuous casting mould 6. A further tundish 4′ is indicated bydashed-dotted lines in a standby position on the casting platform 1.

On this casting platform there are a wide variety of possibilities forhaving a robot carry out process-controlled and automated interventionson the casting installation, for which either the operation of a numberof stationary robots or the operation of at least one mobile robot isnecessary. A runway 7 is laid over the casting platform 1 in such a waythat a multiplicity of working areas A₁, A₂, A₃, A₄ can be served by asingle robot 8, starting from a number of operating positions E₁, E₂, E₃along the runway. The robot 8 is located in a waiting position in theparking position P₁ at one end of the runway 7. A further parkingposition P₂, which can likewise be used, is located at the opposite endof the runway 7. Supply areas V₁, V₂, V₃ are provided at auxiliarydevices H₁, H₂, H₃ on the casting platform and these are assigned tooperating positions E₁, E₂, E₃ and are set up within the range of therobot arm 15. If the space conditions on the casting platform do notallow this, individual supply areas may also be set up outside the rangeof operating positions of the robot. The operating time of the robot forthe completion of an intervention is then extended however by the periodof time taken for necessary supplying movements.

From the operating position E₁, the robot 8 can carry out interventionsin the working areas A₁ (casting ladle) and A₄ (tundish) which relate tothe ladle nozzle 3 and the shroud, and also the pouring-in area of thetundish 4. Among the activities to be carried out at time intervals inthese working areas are, for example, changing of the shroud, burningclear the ladle nozzle or feeding the casting powder into the tundish.The spare parts and utilities necessary for these interventions, such asfor example a replacement shroud, the necessary specific casting powderof the predetermined quality and amount or a burner, are taken by therobot from the assigned supply area V₁, where these utilities are keptreadily available in stock at predetermined places of the store of theauxiliary device H₁.

Starting from the operating position E₂, the robot 8 can carry outinterventions in the operating areas A₂ (mould) and A₄ (tundish) whichrelate to the pouring-out area of the tundish 4, the submerged castingtube 5 and the opening on the inlet side of the continuous casting mould6. Among the activities in these working areas are for example feedingcasting powder into the tundish, changing of the submerged casting tube,burning clear the tundish outlet opening, feeding casting powder intothe mould, observing the level of the bath in the mould, taking samplesfrom the mould, etc. The utilities and spare parts necessary for theseinterventions, such as for example a casting powder appropriate for thequality of steel to be cast and the casting conditions at the giventime, submerged casting tubes, sublances etc, are taken by the robotfrom the auxiliary device H₂ in the supply area V₂.

Starting from the operating position E₃, the robot 8 can performinterventions on a further tundish 4′ in the working area A₃ (tundishchanging stand), taking the required utilities from the auxiliary deviceH₃ in the supply area V₃.

The parking position P₂ is available to the robot as a second parkingposition if only one robot is provided on the casting platform.Alternatively, a further robot 8′ may wait at the parking position P₂ toperform operations, whereby a much more efficient plan of action can berealized. If, for example, interventions of equal priority, neither ofwhich can be delayed, must be carried out both in the working area A₁and in the working area A₂, the control system or the process computerwill direct the robot 8 from its parking position P₁ to the operatingposition E₁ and the robot 8′ from its parking position P₂ to theoperating position E₂ assigned to it.

FIGS. 2 and 3 show a robot 8 in two operating positions E₁ and E₂ on thecontinuous casting installation. The continuous casting installation isindicated with dashed lines by the outer contours of the casting ladle2, the tundish 4 and the continuous casting mould 6. The runway 7 of therobot is formed by two running rails 9, 9′, which are taken in astraight line past the tundish 4 and the continuous casting mould 6 at adistance above the casting platform 1. Fastened to the travellingmechanism 10 is a robot swiveling mechanism 11 with a jib 12, which canassume two positions that are swiveled by 90° in relation to each otherand cover the operating positions E₁ and E₂. The robot is arranged in asuspended manner on the extending end of the jib 12 and can assume thetwo operating positions E₁ and E₂. The jib 12 is represented in theoperating position E₁ by dashed-dotted lines and in the operatingposition E₂ by solid lines. The kidney-shaped range lines 13, 14 in FIG.2 and the circular range lines 13′, 14′ in FIG. 3 illustrate the workingareas A₁ and A₂ of the robot arm 15. Within the working area A₁, whichis assigned to the operating position E₁, all the main areas of thecasting ladle 2 up to the mould 6 can be reached by the robot 8. Fromthe second operating position E₂, interventions can be performed in theworking area A₂, preferably in the transitional area from the tundish 4to the continuous casting mould 6 and on the latter itself. In an areaat the edge of the casting platform, the robot is assigned a parkingposition P₁. Also provided in the direct vicinity of this parkingposition is a supplying position V₁, from which the robot can take allthe auxiliary items required for its operation. Independently of thecasting operation that is in progress, manual preparation work for theoperation of the robot can be performed undisturbed and in safety inthis parking position.

On the casting platform 1 there is the control stand 18, from which thecontinuous casting installation is monitored and operated in a largelyautomated manner by a process computer or a central control device. Theprocess computer 19 or the central control device and also theindividual robot or number of robots are assigned data transmitting anddata receiving devices 20, 21, via which all the information necessaryfor carrying out the interventions are transmitted, preferably on aradio link.

In order to bring the robot into favourable operating positions, variousspecial designs of the runway are possible. FIG. 4 shows a raisable andlowerable runway section 22 of the runway 7, with which the robot 8, ofwhich only the lower base part is represented, is lifted into a raisedintervention position E with respect to the plane of the runway. Therunway section 22 is supported on lifting cylinders 23, and isappropriately positioned by these. In its intervention position E, whichfor its part is determined by a robot rotating axis in the base region,the robot 8 is definitively fixed in its position on the runway section22 by an arresting device 24, and consequently a fixed point that isimportant for the robot control is defined.

FIG. 5 shows a runway section 27, which can be swiveled about a verticalswivel axis 26 into a predetermined angular position, in its startingposition in line with the runway 7 and in a swiveled-out position, whichdefines the intervention position E for the robot. The runway section 27can be made to move in a horizontal plane on rails 29 set up in the formof an arc of a circle.

In addition, branches can be used on the runway, using conventionalpoints known from the railways. Upward sloping sections and downwardsloping sections may be provided on the runway, it being possible forexample to use cogwheel mechanisms to overcome upward and downwardslopes.

The invention is not restricted to the use of particular types of robot.Particularly suitable for use on the casting platform of a continuouscasting installation are buckling-arm robots or portable robots, as areuniversally offered by many manufacturers for the widest variety ofoperating possibilities and with special adaptations.

1. Continuous casting installation with at least one robot for carryingout process-controlled or automated interventions on a continuouscasting installation and accessing assigned auxiliary devices, whereinthe continuous casting installation is assigned a runway, the robot isassigned a travelling mechanism and the travelling mechanism isdisplaceably guided on the runway, at least one parking position and atleast two operating positions are defined for the robot on the runwayand each operating position is assigned working areas on the continuouscasting installation that can only be reached from this operatingposition, the distance between each operating position of the robot andthe assigned operating area or supply area (V1, V2, V3) is fixed withinthe minimum and maximum range of the robot arm (15) and the robot isequipped with a data transmitting and receiving device and the latter isconnected by signalling technology to a central control device or aprocess computer of the continuous casting installation.
 2. Continuouscasting installation according to claim 1, wherein the runway is formedby a track system.
 3. Continuous casting installation according to claim1, wherein the runway is formed by at least one running rail of anoverhead monorail conveyor.
 4. Continuous casting installation accordingto claim 1, wherein the runway has branches (points).
 5. Continuouscasting installation according to claim 1, wherein a runway section isformed in such a way that it can be adjusted in height or can beswiveled.
 6. Continuous casting installation according to claim 1,wherein the travelling mechanism is assigned a robot swiveling mechanismand at least two operating positions are defined for the robot with theswiveling position of the robot swiveling mechanism, the swivelingmechanism preferably comprising a jib, on the extending end of which therobot is arranged.
 7. Continuous casting installation according to claim1, wherein the robot is fixed in its operating position by an arrestingdevice.
 8. Continuous casting installation according to claim 1, whereineach operating position of the robot on the runway is assigned at leastone operating area at the continuous casting installation and a supplyarea at an auxiliary device (tool store, utilities store).
 9. Continuouscasting installation according to claim 1, wherein the runway isarranged on the casting platform, preferably in a horizontal plane. 10.Continuous casting installation according to claim 1, wherein a numberof robots, preferably two robots, are assigned to a single runway. 11.Method for operating a continuous casting installation including atleast one robot which can be displaced on a runway between a parkingposition and at least two operating positions, wherein control signalsare issued from a process computer or a central control device to therobot and, on the basis of these control signals, a selected operatingposition is moved to and automated interventions on the continuouscasting installation are performed by the robot, the control signals forthe interventions to be carried out on the continuous castinginstallation being issued by the process computer or a central controldevice to the robot in the sequence of the priority of the interventionsto be carried out.
 12. Method according to claim 11, wherein measurementdata are gathered by the robot on the continuous casting installation,these measurement data are transmitted to the process computer or acentral control device, are processed by the process computer or thecontrol device and results of this data evaluation are converted intocontrol signals for the robot or the continuous casting installation.13. Method according to claim 11, wherein, of at least two robots whichcan be made to move on a runway, a first robot which can be made to moveon the runway, as the primary robot (master), receives all the controlsignals and carries out interventions on the continuous castinginstallation and a further robot which can be made to move on therunway, as the auxiliary robot (slave), is preferably assigned to aparking position.
 14. Method according to claim 13, wherein, if there isa conflict of priorities of control signals, the primary robot and theauxiliary robot are activated both robots are directed to the respectiveoperating positions while excluding the possibility of them hinderingone another.
 15. Method according to claim 12, wherein, of at least tworobots which can be made to move on a runway, a first robot which can bemade to move on the runway, as the primary robot (master), receives allthe control signals and carries out interventions on the continuouscasting installation and a further robot which can be made to move onthe runway, as the auxiliary robot (slave), is preferably assigned to aparking position.